1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus such as a copying machine or printer, which forms an image on a recording medium by using an electrophotographic image forming process.
2. Related Background Art
In a conventional multicolor electrophotographic image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and a process means acting thereon are integrated into a cartridge, and the cartridge is detachably mounted in the electrophotographic image forming apparatus. That is, this apparatus uses a process cartridge scheme (a developing unit is mounted separately). According to this process cartridge scheme, since maintenance of the apparatus can be performed by the user himself/herself instead of a serviceman, a great improvement in operability can be attained. For this reason, this process cartridge scheme is widely used in multicolor electrophotographic image forming apparatuses.
In such a process cartridge scheme, a process cartridge is inserted into the mounting means of an electrophotographic image forming apparatus body and fixed at a predetermined position. Developing rollers for different colors are selectively pressed against the electrophotographic photosensitive member of this process cartridge or the electrophotographic photosensitive member directly mounted on the electrophotographic image forming apparatus body.